/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.    
 */

package org.apache.bifromq.basekv.store.util;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.RejectedExecutionException;

public class ExecutorServiceUtil {
    public static CompletableFuture<Void> awaitShutdown(ExecutorService executor) {
        if (executor.isShutdown()) {
            return CompletableFuture.completedFuture(null);
        }
        CompletableFuture<Void> onDone = new CompletableFuture<>();
        try {
            executor.submit(() -> {
                onDone.complete(null);
            });
        } catch (RejectedExecutionException ree) {
            onDone.complete(null);
        } finally {
            executor.shutdown();
        }
        return onDone;
    }
}
